ESR1 and endometrial cancer: In our earlier study of the ESR1 gene, we investigated the PvuII, XbaI, codon 243, codon 325 variants, and a 5′ promoter microsatellite (rs2234670), and found the PvuII and XbaI variants as well as the microsatellite to be associated with endometrial cancer risk (Wedrén et al, 2008).